1. Field of the Invention
The invention relates to a lens system, and more particularly, to a variable or adjustable power lens device.
2. Prior Art
Variable focus lenses of various types are disclosed. For example, U.S. Pat. Nos. 4,373,218 and 4,190,330 disclose liquid crystal devices. In these prior art systems, the liquid crystal element is a relatively thick film, and thus requires relatively high activation power. U.S. Pat. No. 4,373,218 discloses a variable power intraocular lens formed of an expandable sack for implantation into the anterior chamber of a human eye. The lens may be a liquid crystal device controlled by a separate microprocessor. The liquid crystal material is contained within the expandable sock. U.S. Pat. No. 4,190,330 discloses the use of liquid crystal material in a complex dual lens configuration in which the focal length is varied by application of an electromagnetic field such as a magnetic field produced by an induction coil surrounding the entire lens structure. In U.S. Pat. Nos. 4,222,641; 4,016,094; and 3,499,112 various liquid crystal matrix devices are disclosed for color and light control. However, there is no system providing variable cylinder power and axis, prism power and axis, light and color in addition to sphere.
Other prior art of some relevance is disclosed in the following U.S. Pat. Nos.: 29,684, Gordon; 3,673,616, Fedorov et al; 3,974,331, Pepin; 3,976,874, Lange et al; 3,980,880, D'Agostino; 3,982,239, Sherr; 4,019,807, Boswell et al; 4,044,546, Koike; 4,050,814, McFadden; 4,143,265, Krappatsch; 4,239,345, Berreman et al; 4,241,339, Ushiyama; 4,272,910, Danz; 4,279,474, Belgorod; 4,300,818, Schachar; 4,332,039, LaFuente; 4,362,933, Kroener et al; 4,368,386, Huignard et al; 4,374,325, Howorth.